Double stage valve for pumps or the like



United States Patent DOUBLE STAGE VALVE FOR PUMPS OR THE LIKE Irvin E. Wiegers, Hamilton, Ohio, assignor to Hamilton- Tihgllrllas Corporation, Hamilton, Ohio, a corporation 0 10 Application April 20, 1953, Serial No. 349,773

14 Claims. (Cl. 10339) This invention relates to a double stage valve for pumps or the like and concerns itself primarily with a valve structure connected with the inlet and outlet of the pump and with an air dome which canbe put into communication with either the pump inlet or pump outlet to maintain high efliciency at varying pressures.

It is well known that pumps, especially of the centrifugal type function very efliciently for propelling fluids within the pressure range for which they are designed. But if this pressure is exceeded, the efliciency of the pump is greatly reduced and may be, reduced to such a point that the flow of fluids entirely ceases. In the past, it has been necessary to provide multiple stage pumps to meet the higher pressure requirement.

At the present time, it is impracticable to provide a centrifugal pump which is eflicient at widely varying discharge pressures. In general such pumps are designed for the highest discharge pressure encountered, but the efliciency thereof is reduced when pumping at low discharge pressures.

It is an object of this invention to overcome the objections above noted in the provision of a novel valve for automatically double staging a centrifugal pump or centrifugal compressor when the discharge pressure rises above a point at which the pump or compressor can efiiciently deliver.

The invention comprises the novel structure and combination of parts hereinafter described and more particularly pointed out and defined in the appended claims.

In the accompanying drawing which illustrates a preferred form of this invention and in which similar refer ence numerals refer to similar features in the different views:

Fig. 1 is an elevational view of a centrifugal pump, a double staging valve and part of an air dome involving this invention, and

Fig. 2 is a sectional view through the valve with the piping and part of the dome shown in elevation.

In referring now to the drawing, especially to Fig. 1, there is shown a centrifugal pump 3 having an inlet pipe 4 with a check valve 5 of well known construction and an outlet or discharge pipe 6 with a check valve 7 of usual construction. The inlet pipe 4 is connected by a vertical pipe 8 with the top of the vertically extending double staging valve housing 9 while the discharge pipe 6 is connected by a vertical pipe 10 with a lower portion of the valve housing.

The valve housing 9 which is vertically arranged at a distance above the pump 3 has a neck portion 11 into which the pipe 8 is secured and which neck portion forms a chamber 12 between the pipe 8 and the body of the valve housing. The body of the valve has an opening 13 in the neck portion. A spider 14 is slidably mounted in the opening 13. At the interior of the opening 13, there is 2,779,290 Patented Jan. 29, 1957.

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2 spider 14 by a bolt 17. From the bottom of the base 16b, there extends a rod 18 having a flat side 18a and a lower cylindrical portion 18b which slidably extends thru :an opening 19 in the valve housing.

A crank arm 20 is pivoted at one end to the flat side of the rod 18 while the other end. of the crank arm is pivoted to one end of a lever 21 extending downwardly in the valve housing. This lever is pivotally mounted at its medial point upon a rod 22 extending transversely of the housing and supported thereby. The free end of the lever 21 is pivotally connected to one end of a crank arm 23; the other end of the crank arm being pivoted to a reciprocating valve rod 24 having a cylindrical portion.

24a extending into a bore 25 in a projection 26 on the valve housing.

The end of the rod 24 opposite the portion 24a is connected to a spider 27 slidably mounted in a valve opening 28 in the valve housing. A lower valve 16 similar to the upper valve 16 is connected to the spider 2'7 and is adapted for engaging a seat 15 surrounding the valve opening 28 for closing the opening. The lower valve 16 at the opening 28 is in a neck 11a on the valve housing and is normally held open by the spring pressed valve 16.

The valve rod 18 of the upper valve 16 extends thru the valve housing and is connected to a diaphragm 29 which is confined between the plates 30 and 31 threaded on the lower end of the valve rod 18. The circumferential portion of the diaphragm 29 is secured between a flange 33 extending from the valve housing and a flange 34 on the end of a thimble-like casing 35 extending lat-, erally from the valve housing. The flanges 33 and 34,

are connected by bolts 33a.

An adjustable screw 36 is threaded in the closed end of the casing 35. This screw has a cylindrical end 3611 which extends into a bearing socket 37 in a head 38 having a fiange 38a which forms a seat for a coil spring 39 positioned between the flange 38a and the plate 31 at the diaphragm 29. This spring 39 may be adjusted to vary the pressure against the diaphragm 29 by adjusting the screw 36. Thus the spring 39 determines the pressure that is intended and when this pressure is exceeded by the upper pump pressure, the valve 16 will snap open and the lower valve 16 will be snapped to closed position. This action is due to the unbalanced pressure differential across the upper valve 16.

An air dome 40, a part only of which is shown is connected by a pipe 41 with the upper end of the valve housing 9 and is above the water line in the system. This air dome is in communication with the interior of the valve housing and is in communication with whichever valve 16 that may be open. The valve housing is provided with apertures 42 which communicate with fluid chamber 43 located between the diaphragm 29 and the valve body 9 for influencing the diaphragm.

In normal operation, the air dome pressure will vary with the pressure of the pump discharge. When the pressure exceeds an amount which is determined by the load- 5 will prevent reverse flow down the inlet pipeS. The pump discharge pressure will be increased by the amount of the pressure provided by the air dome. During the time that the upper valve 16 is opened, the air dome pressure will fall continuously to a point at which it will: be possible for the diaphragm spring 39 to snap open the lower valve 16, and through the lever 21 close the upper valve 16.and again connecting the pump discharge with the air dome. This cycle of operation will be automaticaily repeated "as long as the 'pump discharge pressure remains" above "a pressurefixed 'by the diaphragm loading spring 39.

The successful operation of this double stage valve depends on the snap action of the valves 16. "For if the valve sh'ouldstopat some mid position with thevalves 16 partlyopen, the valve will simply bypass the pump pressure and the pump efficiencywillbe reducedor'destroyed. The snap action of the valves 16 .is obtained by the balanced pressure exerted on the valves 16 when either one is in closed position. This valve structure will have a hired differential, the difference in airdome pressure between the opening of lower valve 16 an d'the opening of upper valve 16. Of course, "it will be'un'derstood that through the action of lever '21'the opening of one valve will cause the closing of the other'valve. This differential can be 'varied by changing the effective area of the diaphragm 29. During operation, the air dome 40 supplies an elastic pressure.

During operation, thedischarg'e through the check valve 7 in the outlet pipe pulsates during the time that the-double stage effects are obtained and steady during low pressure operation.

While the description of the 'double stagingvalve has been in conjunction with a centrifugal pump, it maybe used with a compressor in refrigeration, with positive displacement pumps and compressors or similar applicances.

It will be appreciated that this invention will eliminate the use of multiple stage pumps and will maintain the efliciency of centrifugal pumps or compressors that excee'd the discharge pressures for which they were designed.

I am aware that many changes may be made and various details of construction may be modified without departing from the principles of this invention so I do not propose limiting the patent granted otherwise than necessitated by the appended-claims.

Iclaim:

1. In an apparatus of the class described, a pump having an inlet and an outlet, a valve housing having pipe connections with said inlet and outlet, valves in said housing for controlling said pipe connections, an air dome above the water line of said pump connected to said valve housing, pressure responsive means connected to said valves for normally maintaining one valvecl'osed and the other valve open and in communication with said air dome whereby excessive pressure in said pump will open the closed valve and connect the normally closed connection with said air dome and cause the other valve to close.

2. In a double stage valve structure for a purnp having r an inlet and an outlet, a valve housing, saidhousing having a valve opening in its periphery, a valve in said housing for controlling said opening, said housing having a, second valve opening in its periphery in spaced relation 'to the first valve opening, a second valve for controlling said second opening, a lever having means connecting said valves for opening one while closing the other, a spring loaded diaphragm subject to pressure in said housing and connected to the first mentioned valve for normally maintaining the same in closed position and the other valve in open position and an air dome connected to said valve housing and normally in communication with said open valve, and pipes connecting said valve openings with the inlet and outlet of said pump.

3. In a double stage valve, a housing having a valve opening adapted to be connected to the inlet of a pump and having a second valve opening adapted to be connected to the outlet of apump, a valve controlling the first mentioned opening and having a stem, a diaphragm connected to said stem, a spring acting against said diaphragm, means supporting said diaphragm and spring adjacjcnt said housing means operatively associated with said spring for adjusting'said spring, a valve for controlling said 'se'co'nd valve opening and having a stem, a lever haviii ing crank connections with said stems whereby the openingof-onevalve will close the other valve and an airdome connected to said housing for the purpose set forth.

4. In an apparatus of the class described, a pump having an inlet and an outlet, a valve housing having pipe connections with said inlet and outlet, valves in said housing for controlling said inlet and outlet connections, means connecting said valves whereby when one is closed, the other is opened, an air dome connected to said housing and normally communicating with the outlet connection, yielding means operatively connected with said first-mentioned means for normally maintaining said inlet valve in closed position and said outlet valve in open position, said yielding means being actuated by a predetermined pressure arising in said outlet for opening said inlet valve and closing said outlet valve.

5. In an apparatus of the class described, a valve housing having spaced openings in its periphery, valves controlling said openings, said valves having stems, means connecting said stems for closing one valve and simultaneously opening the other valve, a diaphragm attached to one of said stems, means defining an air chamber between said'diaphragm and housing, said chamber having ports communicating with the interior of said housing, yielding means acting against said diaphragm for normally closing the'said 'on'e valve, and an air dome connected to said housing for communicating with the interior of said housing whereby pressure in said housing overcoming the force of said yielding means will act against said diaphragm for opening the one said valve and closing the other.

6. In an apparatus of the class described, a valve housing having an opening, a valve controlling said opening, said valve having a "stem, a diaphragm on said stern and secured in spaced relation to the Wall of said housing, yielding means acting against said diaphragm for normally closing said valve, said housing having a second opening, a valve controlling said second opening, said second valve having a stem in substantial parallel relation with the first mentioned stem, means operatively connecting said stems whereby the opening of one valve will close the other and an air dome'connetcted to said housing for communicating with said valve and diaphragm for deflecting said diaphragm for opening the first valve when the pressure in said housing exceeds the force of said yielding means.

7. In an apparatus of the class described, a valve housi'ngh'aving spaced openings in its periphery, valves controlling said openings, said valves having stems, a lever pivoted at its medial point and having its ends in crank connection with said stems, one of said stems extending thru the lateral wall of said housing, a diaphragm secured to the outer end of said one stem, said housing having a flange for supporting the outer margin of said diaphragm in spaced relation to said housing for providing an .air chamber between said housing and diaphragm, a casing having a flange attached to the flange on said housing over said diaphragm, an adjustable spring in said casing acting against said diap'rgam, said housing having ports communicating with chamber and an air dome connected to said housing for the purpose set forth.

8; In an apparatus of the class described, a valve housing having an opening adapted for connection to the intake side of a pump, a valve controlling said opening, means co-operating with said housing for forming an air chamber communicating with the interior of said housing, a diaphragm secured in said chamber and connected to said valve, yielding means acting against said diaphragm for normally maintaining said valve in closed position, said housing having a second opening adapted for connection with the outlet of a pump, a valve controlling said second opening, means including a lever connecting said valves whereby when the first valve is closed, the second valve is opened and an air dome connected to said housing for communicating With the open valve and the air chamber for the purpose set forth.

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9. In an apparatus of the class described, a pump having an inlet and an outlet, a valve housing having pipe connections with said pump inlet and outlet, valves in said housing for controlling said inlet and outlet connections, each valve having a stem, means connecting said stems for opening one valve and closing the other, means associated with said valve housing for forming a chamber, a diaphragm mounted in said chamber and connected to the stem of said valve controlling the inlet pipe connection, adjustable yielding means acting against one side of said diaphragm for normally closing the pipe connection to the pump inlet, the other side of said diaphragm being subjected to the pressure in said valve housing for opening said inlet valve pipe connection and an air dome connected to said valve housing and communicating with the said other side of said diaphragm.

10. In an apparatus of the class described, a double stage valve housing having a diaphragm chamber and upper and lower valve openings, a pump having an inlet and an outlet, a pipe connecting the inlet with the upper valve opening and a pipe connecting the outlet with the lower valve opening, valves in said housing for controlling said valve openings, means connecting said valves whereby when one is moved to closed position the other is moved to open position, the upper valve having a stem extending into said chamber, a diaphragm extending across said chamber and fixed therein and connected to said diaphragm, an adjustable spring positioned against the far side of said diaphragm and normally effective for closing the upper valve, the near side of said diaphragm being exposed to the pressure in said housing and an air dome above the water line of said apparatus and connected to said valve housing.

11. In an apparatus of the class described, a pump having an inlet and an outlet, a valve housing having pipe connections with said inlet and said outlet, an air dome having a pipe connection with said valve housing, valves in said housing for controlling said pipe connections, means defining a diaphragm chamber in connection with said housing, a diaphragm secured in said chamber and connected to the valve controlling the inlet pipe connection, a spring acting against the far side of said diaphragm, the near side of said diaphragm being exposed to the pressure of said air dome and means connecting said valves whereby when one is opened the other is closed.

12. In an apparatus of the class described, a pump having an inlet and an outlet, a valve housing having pipe connections with said inlet and outlet, an air dome having a pipe connection with said housing, valves in said housing for controlling said pipe connections, a diaphragm associated with said housing and having a connection with one of said valves, yielding means acting against one side of said diaphragm for normally closing the valve connected thereto, the other side of said diaphragm being exposed to the air pressure from said air dome and means connecting said valves whereby when one is opened the other is closed.

13. In an apparatus of the class described, a pump having an inlet and a discharge outlet, a valve housing having spaced pipe connections with said inlet and outlet, an air dome having a pipe connection with said housing, valves in said housing for controlling said pipe connections to said pump, yielding means acting against one of said valves for normally moving the same to closed position, a pressure controlled diaphragm connected to the last mentioned valve for opening the same when the pump pressure overcomes the pressure of said yielding means, and means connecting said valves for closing one While opening the other.

14. In an apparatus of the class described, a pump having an inlet and an outlet, a valve housing having spaced pipe connections with said inlet and outlet, an air dome having a pipe connection with said valve housing, valves in said housing for controlling the pipe connections to said inlet and outlet, means connecting said valves for closing one and opening the other, and yielding means exposed to the pressure of said air dome and having a connection with the valve controlling said inlet connection for the purpose set forth.

References Cited in the file of this patent UNITED STATES PATENTS (Addition to 908,636) 

